This invention relates generally to flexible packages, and, more particularly, to flexible packages for holding products, such as foods, under vacuum therein, and which, once opened, are arranged to readily pour the contents therefrom via a pour-spout, and then to be readily re-closed to keep the contents fresh, until the package is again reopened to pour more of the contents therefrom.
Various types of flexible packages for holding particulate materials, e.g., ground or whole bean coffee, chemicals, etc., under vacuum therein have been disclosed in the patent literature and are commercially available today. Examples of such packages are found in the following U.S. Pat. No.: 4,576,285 (Goglio), U.S. Pat. No 4,705,174 (Goglio), and U.S. Pat. No 4,913,561 (Beer).
The major advantages of flexible packaging, as compared to relatively rigid packaging, e.g., cartons, are that until the flexible package is filled it takes up very little volume, and after it is emptied of its contents, it readily collapses, thereby reducing its volume to approximately that of the unfilled package. The former characteristic is a significant advantage insofar as storage is concerned, while the latter characteristic is a significant advantage from the standpoint of being disposable.
One common type of flexible package for holding goods under vacuum until the package is opened is the so-called "gusseted" package or bag. Typically, such a package is formed from a web of flexible stock material, e.g., polyethylene, polyester, polypropylene, metal foil, and combinations thereof in single or multiple plies, into a tubular body, having a face panel, a back panel, and a pair of gusseted sides. Each gusseted side is formed by a pair of gusset sections and a central fold edge interposed between a pair of outer fold edges. The lower end of the bag is commonly permanently sealed, e.g., heat sealed, along a line extending transversely across the width of the bag close to its bottom edge. The top of the bag is commonly sealed transversely across the entire width of the bag in a number of ways to maintain the contents under vacuum until the bag is opened. Such action is frequently accomplished via a readily openable mouth, which, when opened, provides access to the contents of the bag. For example, in one prior art package, the top seal is made peelable by modifying the sealant layer with a peelable coating or incompatible additive. Thus, when the seal is peeled apart, the unsealed portions form an open mouth through which the contents of is the package may be removed. Another approach to providing an opening or mouth for a flexible package is that of the heretofore identified U.S. Pat. No. 4,705,174 (Goglio). That package includes a peel strip applied to the inner surface of the package below the top edges. The strip provides an air-tight interfacial seal which can be readily peeled apart to provide access to the interior of the package. Another approach to providing an opening or mouth for a flexible package is to score the upper flap of the package by laser or mechanical means through a tear initiation resistant layer(s) of the package structure. In this way, the package can be opened by tearing away the scored area to form the package's mouth. Gusseted bags, particularly those for foods, frequently make use of a plastic coated wire tie to serve as closure for the bag. In particular, the wire tie is designed to close the mouth of the bag after it has been initially opened so that the re-closed bag will keep its contents fresh. Whether or not such wire-tie closures effectively provide a positive means of re-closing a gusseted package is open to debate. Moreover, the effectiveness of such closures is frequently dependent upon the manner in which the wire tie is used. Thus, there is a perception in some quarters of the consuming public that a wire-tie package cannot be re-closed securely enough to maintain product freshness over an extended period of time. Therefore, such packages have not been fully accepted as being truly reclosable.
In U.S. Pat. No. 5,692,837 (Beer), which is assigned to the same assignee as this invention and whose disclosure is incorporated by reference herein, there is disclosed a gusseted flexible package having a integrated snap closure for re-closing and resealing the package after it has been initially opened. In particular, that package has an interior for initially holding some product, e.g., whole coffee bean or ground coffee, under vacuum, and which includes a mouth portion arranged to be peeled open to provide access to the contents of the package. The package is formed of a flexible material and includes a front panel, a rear panel, and a pair of opposed side gussets. The panels and gussets each include a top portion, which, between them, define the package's mouth. A peelable closure is provided within the mouth. A snap closure is provided above the peelable closure. The package is arranged to be sealed under vacuum, with the peelable closure maintaining the vacuum within the package until it is peeled open. The snap closure comprises a pair of snap strip members secured to respective portions of the front and rear panel. The snap strip portions are arranged to be releasably snap fit together with portions of the closure extending through opening in the side gussets, so that the snap strip portions can be opened and reclosed after the peelable closure has been peeled open in order to provide repeated access to the interior of the package, while minimizing the ingress of air into the package when it is closed.
In copending U.S. patent application Ser. No. 09/231,337, filed on Jan. 13, 1999, entitled Snap Closure For Flexible Packages And Flexible Packages Including The Same, which is assigned to the same assignee as this invention and whose disclosure is incorporated by reference herein, there are disclosed closures for gusseted flexible packages and gusseted flexible packages including such closures. The package is formed of a flexible material and includes a front panel, a rear panel, and a pair of opposed side gussets. The panels and gussets each include a top portion, which between them define the package's mouth. The package's mouth is initially sealed but arranged to be opened, e.g., peeled apart. The snap closure enables the resealing of the mouth of the package and is made up of a pair of elongated elements, one of which includes a tongue extending along the length of it. The other element includes an undercut groove extending along the length of it. The elements are arranged to be pressed together, whereupon the tongue of the one element enters the groove of the other element with portions of the panels and side gussets tightly interposed therebetween. The closure elements may be a part of the package or a separate component for use therewith. In any case, when the closure is utilized, it recloses the mouth of the package to preclude or minimize the ingress of air into the package.
Other prior art closures for packages are found in U.S. Pat. No.: 4,988,216 (Lyman), U.S. Pat. No 5,037,138 (McClintock et al.), 5,059,036 (Richison et al.), U.S. Pat. No 5,147,272 (Richison et al.), U.S. Pat. No 5,738,444 (Lantz et al.), D350,696 (aslund), and in Japanese Application 6127557 (May 1994), and United Kingdom Patent 1,008,068 (October 1965). In addition, Weland M. AB, a Swedish Corporation, sells a "CLIP-it" fastener for bags or packages and Carolon Company of Rural Hall, NC. sells a packaging system, including an ice bag and fastener for sealing the ice bag, under the trademark "CHAMP INSULATED PROPAC II." The "CLIP-it fastener" comprises a clip having one portion including a pair of ridges and another portion which includes a tapered groove into which the pair of ridges is directed to sandwich the walls of the bag being closed. In order to hold the clip in place, the portion of the clip including the groove includes a movable snap type fastener which is arranged to releasably secure to an ear or tab portion on the other part of the clip, i.e., the clip including the pair of ridges. The package system of Carolon Company includes a bag and a fastener for the bag. The fastener is arranged to be used to close the bag and includes a pair of sections which are hingedly secured together by a living hinge along the top marginal edge of the fastener. One of the sections includes a C-shaped recess and the other section includes a circular projection mounted on an upstanding flange and which is arranged to be received to be snap fit within the C-shaped recess to hold the walls of the bag therebetween.
While the aforementioned prior art may suitable for their intended purposes, a need still exists for closures for use on gusseted packages which, when opened, establish a pour spout to facilitate the pouring of all or some of the contents from the package and which when re-closed keep the contents of the package fresh, and for gusseted packages including such closures.